The invention relates to a motor-assisted hand-movable pushcart that can be inserted into an identical pushcart in a space-saving manner, whereby the pushcart is provided with a drive chassis having four casters and a pushing device and a storage device for goods, and whereby below the storage device is a support section on which is disposed at least one running wheel that is located between the two front and the two back casters.
Pushcarts of this type are described in more detail in U.S. Pat. No. 4,826,186 and European Patent No. 0 352 647 B1. The at least one running wheel has a stabilizing effect on the steering and pushing process in pushcarts of this type. The running wheels are furthermore disposed in such a way that the pushcarts can be pushed relatively tightly inside each other. In self-service markets, this makes it possible to save much storage space when parking or making available these pushcarts in rows. The advantages just described have caused such pushcarts to be very popular. However, if these pushcarts are heavily loaded, the same amount of pushing force must be applied as for pushcarts with no running wheel in the center. For this reason, pushcarts were developed that are provided with four wheels and/or casters and have a controllable, electromotor-driven drive unit intended to propel or move the pushcart by acting via the wheels or an additional drive wheel. One of many pushcarts of this type is described, for example, in U.S. Pat. No. 5,746,282. The drive unit hereby acts supporting during the pushing of a heavily loaded pushcart by hand. But the pushcarts mentioned last cannot be inserted inside each other in a space-saving manner.
The objective of the invention is to further develop a pushcart of this class type in such a way that if the known advantages that can be obtained with a centered running wheel and by using a controllable drive unit are utilized, the ability of inserting the pushcarts into another, identical pushcart is not adversely affected.
This objective is realized in that at the support section a drive unit supplied by a power source is provided, this drive unit being intended for driving the at least one running wheel, and that the power source on the pushcart is located in at least one of the spaces not required by a pushcart to be inserted into it during the insertion process.
The objects can be achieved with a motor-assisted hand-movable cart that can have a further identical cart inserted into it in a space saving manner, whereby the cart is provided with a drive chassis having four casters, including two front casters and two back casters; a pushing device; a storage device for goods; a support section below the storage device, on which is disposed at least one running wheel that is located between the two front and the two back casters, and an electromotor drive unit, this drive unit being intended for driving the at least one running wheel; and a power source located in a space not required by further cart to be inserted into the cart during the insertion process.
It is advantageous to arrange the drive unit on the support section that exists in any case, since the running wheel is located there. If the support section is arranged so as to be swivelable about a horizontal axis, the weight of the drive unit contributes in pushing the running wheel even more against the ground, in this way increasing the drive force of the running wheel. It is further useful, to arrange the power source that is usually made up of batteries in those spaces not required by one of the two pushcarts when two pushcarts are inserted inside each other. Such areas are usually located below the storage device in the front part of the drive chassis and in the back part below the pushing device, whereby they are in the latter case arranged higher than the storage device, however. In this way, the power source and the drive unit do not adversely affect either the space-saving inserting inside of each other of the pushcarts, nor do they claim space or room on or at the storage device.
The invention is explained in more detail in reference to exemplary embodiments, whereby the exemplary embodiments preferably take their orientation from the construction of those pushcarts described in the initially mentioned European patents.